switch(variable_name)\r\n{\r\n case value1:\r\n \/\/code to be executed if variable_name=value1\r\n break;\r\n case value2:\r\n \/\/code to be executed if variable_name=value2\r\n break;\r\n\r\n default:\r\n \/\/code to be executed if variable_name=value3\r\n}\r\n\r\n<\/pre>\nIt works with Java Enums, Wrapper classes, and the String class as well.<\/p>\n
Points to note while using switch statements in Java:<\/strong><\/p>\n\n- You cannot have duplicate case values.<\/li>\n
- The datatype of the case must be the same as the data type of the switch.<\/li>\n
- The limiting value of a case should either be a constant or a literal. You cannot add variables to the case.<\/li>\n
- The break is useful for terminating the flow of the program after a particular case has been executed.<\/li>\n
- If you do not use the break statement, the flow of the control progresses to the next case.<\/li>\n
- The default case can appear anywhere inside the switch block. However, if it contains case blocks after it, a break statement should be added after the default block; otherwise, the control would slip into the next layers of the block.<\/li>\n<\/ul>\n
Java example to illustrate the use of Switch Case:<\/strong><\/p>\npackage com.dataflair.switchcase;\r\nimport java.util.*;\r\n\r\npublic class SwitchStatement {\r\n\r\n public static void main(String[] args) {\r\n \r\n Scanner sc = new Scanner(System.in);\r\n\r\n int variable;\r\n System.out.println(\"Please enter the variable value\");\r\n \r\n variable=sc.nextInt();\r\n\r\n switch(variable)\r\n {\r\n case 1:\r\n System.out.println(\"The value of the variable = \"+variable);\r\n break;\r\n case 2:\r\n System.out.println(\"The value of the variable =\"+variable);\r\n break;\r\n case 3:\r\n System.out.println(\"The value of the variable =\"+variable);\r\n break;\r\n default:\r\n System.out.println(\"The value of the variable is neither 1 nor 2 nor 3\");\r\n }\r\n\r\n }\r\n}\r\n<\/pre>\nOutput:<\/strong><\/p>\nPlease enter the variable value
\n5
\nThe value of the variable is neither 1 nor 2 nor 3<\/div>\nJava program to illustrate what the break statement is useful for:<\/strong><\/p>\nWe can also try to see what happens if we remove the break statement<\/p>\n
package com.dataflair.switchcase;\r\nimport java.util.*;\r\n\r\npublic class SwitchStatement {\r\n\r\n public static void main(String[] args) {\r\n \r\n Scanner sc = new Scanner(System.in);\r\n\r\n int variable;\r\n System.out.println(\"Please enter the variable value\");\r\n \r\n variable=sc.nextInt();\r\n\r\n switch(variable)\r\n {\r\n case 1:\r\n System.out.println(\"The value of the variable = \"+variable);\r\n case 2:\r\n System.out.println(\"The value of the variable = \"+variable);\r\n case 3:\r\n System.out.println(\"Value of the variable = \"+variable);\r\n default:\r\n System.out.println(\"The value of the variable is neither 1 nor 2 nor 3\");\r\n }\r\n\r\n }\r\n}\r\n\r\n<\/pre>\nOutput:<\/strong><\/p>\nPlease enter the variable value
\n1The value of the variable = 1
\nThe value of the variable = 1
\nValue of the variable = 1
\nThe value of the variable is neither 1 nor 2 nor 3<\/div>\nJava program to illustrate the use of switch statements with strings:<\/strong><\/p>\npackage com.dataflair.java.switchcase;\r\npublic class SwitchStrings\r\n{\r\n public static void main(String[] args) {\r\n String course=\"java\";\r\n switch(course)\r\n {\r\n case \"python\":\r\n System.out.println(\"Python was made by Guido Van Rossum\");\r\n break;\r\n case \"java\":\r\n System.out.println(\"Java was made by James Gosling! It is one of Shraman's favourites!\");\r\n break;\r\n case \"c++\":\r\n System.out.println(\"C ++ was made by Bjarne Stroustrup\");\r\n break;\r\n \r\n }\r\n }\r\n}\r\n<\/pre>\nOutput:<\/strong><\/p>\nJava was made by James Gosling! It is one of Shraman’s favourites!<\/div>\nJava program to illustrate the nested switch case:<\/strong><\/p>\npackage com.dataflair.switchcase;\r\nimport java.util.*;\r\n\r\npublic class NestedSwitch\r\n{\r\n public static void main(String[] args) {\r\n Scanner sc = new Scanner(System.in);\r\n \r\n String course=\"java\";\r\n switch(course)\r\n {\r\n case \"python\":\r\n System.out.println(\"Python was made by Guido Van Rossum\");\r\n break;\r\n case \"java\":\r\n System.out.println(\"What version of Java are you using?\");\r\n int version=sc.nextInt();\r\n switch(version)\r\n {\r\n case 6:\r\n System.out.println(\"That is old school!\");\r\n break;\r\n case 8:\r\n System.out.println(\"Wow, that\u2019s great! Tons of new features!\");\r\n break;\r\n \r\n }\r\n break;\r\n case \"c++\":\r\n System.out.println(\"C ++ was made by Bjarne Stroustrup\");\r\n break;\r\n \r\n }\r\n }\r\n}\r\n\r\n<\/pre>\nOutput:<\/strong><\/p>\nWhat version of Java are you using?
\n8
\nWow, that\u2019s great! Tons of new features!<\/div>\nJava program to illustrate the use of switch case with enum:<\/strong><\/p>\npackage com.dataflair.switchcase;\r\n\r\nimport java.util.*;\r\n\r\npublic class SwitchEnum\r\n{\r\n \r\n enum course \r\n {\r\n AI,ML,WD\r\n \r\n }\r\n public static void main(String[] args) {\r\n Scanner sc = new Scanner(System.in);\r\n \r\n course[] presentcourse = course.values(); \r\n \r\n for(course c:presentcourse)\r\n {\r\n switch(c)\r\n {\r\n case AI:\r\n System.out.println(\"The full form of AI is Artificial Intelligence\");\r\n break;\r\n case ML:\r\n System.out.println(\"Full form of ML is Machine Learning\");\r\n break;\r\n case WD:\r\n System.out.println(\"The full form of WD is Web Development\");\r\n break;\r\n \r\n }\r\n \r\n }\r\n }\r\n}\r\n\r\n<\/pre>\nOutput:<\/strong><\/p>\nThe full form of AI is Artificial Intelligence
\nFull form of ML is Machine Learning
\nThe full form of WD is Web Development<\/div>\nJava program to illustrate the use of switch case with Wrapper classes:<\/strong><\/p>\npackage com.dataflair.javaswitch;\r\n\r\nimport java.util.*;\r\n\r\npublic class WrapperSwitch\r\n{\r\n public static void main(String[] args) {\r\n Integer choice;\r\n System.out.println(\"1. Java\\n 2. Python\\n 3.C++\\n\");\r\n Scanner sc = new Scanner(System.in);\r\n choice=sc.nextInt();\r\n \r\n switch(choice)\r\n {\r\n case 1:\r\n System.out.println(\"Java requires a good knowledge of Object Oriented Programming\");\r\n break;\r\n case 2:\r\n System.out.println(\"Easiest language to learn. Known as executable pseudocode\");\r\n break;\r\n case 3:\r\n System.out.println(\"Best language for competitive programming\");\r\n break;\r\n default:\r\n System.out.println(\"Wrong choice\");\r\n \r\n }\r\n }\r\n}\r\n\r\n<\/pre>\nOutput:<\/strong><\/p>\n1. Java
\n2. Python
\n3.C++2
\nEasiest language to learn. Known as executable pseudocode<\/div>\nRules of Switch Case Statement in Java<\/h3>\n
There are a few rules that have to be understood while using switch case statements in Java.<\/p>\n
![\"Flow](\"https:\/\/data-flair.training\/blogs\/wp-content\/uploads\/sites\/2\/2018\/03\/Flow-diagram-for-the-Switch-Case.jpg\")
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